1. Field of the Invention
The present invention relates to data-warehouse technologies, and more specifically to a method and apparatus for considering transient data also in reports generated based on data eventually stored in a data-warehouse.
2. Related Art
A data-warehouse generally contains a copy of large volumes of data in a form suitable for querying/reporting/analysis. The data is often generated/created after processing of the corresponding data stored in several databases (commonly known as ‘application databases’) that are accessed by corresponding applications. The transfer of consolidated information from application databases to data-warehouse may be viewed as containing Extraction, Transformation and Loading operations, and is thus commonly referred to as ETL process, as is well known in the relevant art.
Reports are often generated from various data, for example, to determine the various trends or to know the status of interest. For example, databases may store data corresponding to sales in corresponding regions/locations, the data may eventually be transferred to a data-warehouse, and the data in the data-warehouse may be analyzed to generate the desired reports. Thus, reports are often generated based on the data stored in data-warehouses.
One problem with the above-noted approach is that the reports would not be based on several pieces of data not yet propagated from the databases to the data-warehouse. This is particularly problematic since the interval between execution of ETL process is often large (e.g., order of days) since the ETL process may require substantial amount of computing resources from databases as well as data-warehouse. Such data not yet propagated to the data-warehouse is referred to as ‘transient data’.
What is therefore needed is a method and apparatus for considering transient data also in environments in which reports are generated based on data stored in a data-warehouse.
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